LOS ANGELES — NASA’s Spirit rover continued probing a tiny Martian trench Sunday that may yield clues about whether there ever was water in the area, and was set to begin a 445-foot (135-meter) drive to a crater.

The rover was sending back data from a 3-inch (7.5-centimeter-deep) trench it studied with a microscopic imager and a Mossbauer spectrometer, an instrument that measures the composition and abundance of iron-bearing minerals.

Scientists hope the minerals can show whether the Red Planet’s ancient environment held liquid water for a long enough time to support the development of life. Spirit dug the trench by running its front wheel over the planet’s surface.

The robot was expected to begin driving early Monday toward a crater nicknamed “Bonneville,” a depression more than 650 feet (200 meters) wide. It will stop about midway at the edge of the area scientists are currently able to see and characterize.